Crowding and violence on psychiatric wards: Explanatory models

Objective: Violence is widely prevalent on acute-care psychiatric wards, an d crowding has been identified as a major risk factor. This paper explores why patients may respond to crowding with violence. Method: We carried out a literature review on Medline, using the key words "violence" and "crowdin g." We conducted an additional hand search of the references collected from the reviewed papers. Results: Factors specific to the relation between cro wding on acute-care impatient psychiatric wards and violence can be divided under the following headings: 1)patient density, privacy, and control; 2) ward architecture; 3) the social organization of psychiatric wards; 4) inte rpersonal space; 5) phylogenic theories; and 6) anthropological theories of human behaviour. Conclusions: We offer explanatory models for this relatio n and suggest strategies to counter the effects of crowding. Recommendation s are made for future studies.